Re: [PATCH v5 06/12] PCI: brcmstb: Add bcm7278 PERST support

[Bjorn Helgaas]

On Tue, Jun 16, 2020 at 04:55:13PM -0400, Jim Quinlan wrote:
> From: Jim Quinlan <jquinlan@xxxxxxxxxxxx>
> 
> The PERST bit was moved to a different register in 7278-type STB chips.  In
> addition, the polarity of the bit was also changed; for other chips writing
> a 1 specified assert; for 7278-type chips, writing a 0 specifies assert.
> 
> Signal-wise, PERST is an asserted-low signal.

s/PERST/PERST#/ to match usage of the signal name in spec.

The PERST bit above is the name of a register bit, so use whatever
matches the STB spec.

> Signed-off-by: Jim Quinlan <jquinlan@xxxxxxxxxxxx>
> Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
>  drivers/pci/controller/pcie-brcmstb.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> index 7c148eb65170..d0e256d8578a 100644
> --- a/drivers/pci/controller/pcie-brcmstb.c
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -83,6 +83,7 @@
>  
>  #define PCIE_MISC_PCIE_CTRL				0x4064
>  #define  PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK	0x1
> +#define PCIE_MISC_PCIE_CTRL_PCIE_PERSTB_MASK		0x4
>  
>  #define PCIE_MISC_PCIE_STATUS				0x4068
>  #define  PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK		0x80
> @@ -685,9 +686,16 @@ static inline void brcm_pcie_perst_set(struct brcm_pcie *pcie, u32 val)
>  {
>  	u32 tmp;
>  
> -	tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
> -	u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
> -	writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
> +	if (pcie->type == BCM7278) {
> +		/* Perst bit has moved and assert value is 0 */

s/Perst/PERST/ or PERST# so it doesn't look like an English word and
to match the STB spec.

> +		tmp = readl(pcie->base + PCIE_MISC_PCIE_CTRL);
> +		u32p_replace_bits(&tmp, !val, PCIE_MISC_PCIE_CTRL_PCIE_PERSTB_MASK);
> +		writel(tmp, pcie->base +  PCIE_MISC_PCIE_CTRL);
> +	} else {
> +		tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
> +		u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
> +		writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
> +	}
>  }
>  
>  static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
> -- 
> 2.17.1
>